The present invention is concerned with the joining of sections of waveguide which are usually sections of rectangular waveguide that are used for the guided transmission of electromagnetic waves. The principles of this invention may be used in interconnecting any sections of waveguide including two straight sections of waveguide or a straight section of waveguide with a waveguide bend. The principles of the invention are particularly useful in interconnecting sections of waveguide prior to brazing wherein at least one of the sections is cast rather than machined. Usually, the waveguide bend is constructed by being cast whereas the straight sections of waveguide are constructed by a machining or extruding operation.
U.S. Pat. No. 3,596,937 to Baldelli discloses one prior art technique for joining, preferably by interlocking, sections of waveguide. This patent discusses in some detail the general objectives that are aimed at in interconnecting these sections. Important factors include mechanical stress at the joint, tightness of the joint, and proper alignment between the waveguide sections.
Although the structure shown in U.S. Pat. No. 3,596,937 is usable for interconnecting sections of waveguide, there have been some drawbacks associated with this technique. For example, when the pieces are snap-fitted together, there is a tendency for the metal to shear thereby resulting in a loose fit at the joint. Other prior techniques show the bending of a side flap to hold the sections together. In practice, it has been found that too many of the side flaps either broke or were too weak to maintain the relative positions of the two sections during brazing.
Accordingly, it is an object of the present invention to provide an improved interlocking technique for joining sections of waveguide prior to brazing usually including a waveguide bend.
Another object of the present invention is to provide a waveguide assembly in which the joined sections are interlocked to insure accurate alignment of the sections prior to brazing.
A further object is to provide an interlocked, preferably dove-tailed joint forming a mechanically strong joint and one that can be made quite tight.
A further object of the present invention is to provide a method of constructing an improved interlock joint between waveguide sections, at the same time providing proper alignment of the sections.